ASTM_D_2454_-_14.pdf

Designation:D245414Standard Practice forDetermining the Effect of Overbaking on Organic Coatings1This standard is issued under the fixed designation D2454;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers the determination of the time-temperature effect of overbaking on the physical and chemicalproperties of organic coatings.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:2D522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD523 Test Method for Specular GlossD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint,Varnish,Conversion Coatings,andRelated Coating ProductsD823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD1308 Test Method for Effect of Household Chemicals onClear and Pigmented Organic FinishesD1640 Test Methods for Drying,Curing,or Film Formationof Organic Coatings at Room TemperatureD1729 Practice for Visual Appraisal of Colors and ColorDifferences of Diffusely-Illuminated Opaque MaterialsD1730 PracticesforPreparationof AluminumandAluminum-Alloy Surfaces for PaintingD1731 Practices for Preparation of Hot-Dip Aluminum Sur-faces for PaintingD2197 Test Method for Adhesion of Organic Coatings byScrape AdhesionD2201 Practice for Preparation of Zinc-Coated and Zinc-Alloy-Coated Steel Panels for Testing Paint and RelatedCoating ProductsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD2794 Test Method for Resistance of Organic Coatings tothe Effects of Rapid Deformation(Impact)D3359 Test Methods for Measuring Adhesion by Tape TestD3363 Test Method for Film Hardness by Pencil TestD6386 Practice for Preparation of Zinc(Hot-Dip Galva-nized)Coated Iron and Steel Product and HardwareSurfaces for PaintingD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic,Nonconductive Coat-ings Applied to Non-Ferrous MetalsD7396 Guide for Preparation of New,Continuous Zinc-Coated(Galvanized)Steel Surfaces for PaintingE805 Practice for Identification of Instrumental Methods ofColor or Color-Difference Measurement of Materials3.Terminology3.1 Definitions:3.1.1 overbaking,nan exposure of the coating to a mod-erately higher temperature or to a longer period of baking,orboth,than recommended by the manufacturer of the coating fornormal curing.3.1.1.1 DiscussionThis condition is in contrast to“heatresistance”which is a parameter relating to the service life ofa coating.4.Summary of Practice4.1 Four panels are prepared and baked at the schedulenormally recommended for the coating.Two of the panels arethen removed and the remaining two are subjected to anadditional overbake in which the time and temperature aremutually agreed upon between the purchaser and the seller.The sets of panels,after a suitable conditioning interval,are1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved Feb.1,2014.Published March 2014.Originallyapproved in 1966.Last previous edition approved in 2008 as D2454 08.DOI:10.1520/D2454-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 then evaluated for the properties that are compatible with thesubstrate.Among these are gloss,color,flexibility,adhesion,impact resistance,and resistance to reagents.Note that glasssubstrates should not be tested for impact,and zinc-coatedsubstrates can influence both flexibility and impact.5.Significance and Use5.1 Most coatings are designed for a specific baking timeand temperature.For a variety of reasons(line stoppages,rerouting back through ovens,oven overheating,etc.)theprescribed time or temperature,or both